Build an Automatic Outdoor Security Floodlight Timer with Arduino Uno, PIR Sensor & LDR

Every part needed, pre-tested for compatibility, with an AI build companion trained on this exact project. Shipped from Bengaluru in 3-5 days.

Imagine stepping onto your dark porch and having a floodlight switch on for exactly two minutes — then turn itself off, completely hands‑free, while ignoring motion during the day. This kit guides you through building that exact security light, using an Arduino Uno, HC‑SR501 PIR sensor, and a separate LDR circuit to lock out daytime triggers. You’ll wire real components, write timing logic, and test a system that mimics commercial motion lights — but you built it yourself.

What You'll Build

You’ll assemble a breadboard‑based controller that reads a PIR motion sensor and activates a 12V relay for precisely two minutes whenever movement occurs after dark. A second LDR monitors ambient light and disables the PIR trigger during daylight, so the floodlight never turns on when it isn’t needed. The final assembly is a standalone module you can mount in a weatherproof enclosure and connect to any 12V DC outdoor floodlight for reliable, energy‑conscious security.

What You'll Learn

• Program Arduino delay routines and event‑based timing for real‑world sensors
• Interface an HC‑SR501 passive infrared motion sensor and interpret its signal
• Design an LDR voltage divider to create a daylight‑sensing lockout circuit
• Drive a 5V relay module safely using a flyback diode to switch 12V loads

Kit Contents

Why Buy This Kit Instead of Sourcing Parts Separately

Who This Kit Is For

This intermediate kit is ideal for CBSE Class 11‑12 students exploring physics or computer science projects, B.Tech ECE/EEE undergraduates prototyping for Smart India Hackathon, and ATL tinkering labs introducing sensor‑based automation. Makers aged 15 and up who want a practical, deployable security light will appreciate how it blends hardware interfacing with real‑world timing code — a tangible upgrade over theory‑only exercises.

Built and Backed by Compoden

Every Compoden kit ships with an AI build companion trained on this exact project — accessible via a QR code on the box, with WhatsApp and email backup. We’ve spent 10 years building projects for makers, schools, and institutions across India. If a part fails because of a manufacturing defect, replace it free within 7 days.